There has been a 10-fold rise in reported cases of a toxin produced by bacteria associated with MRSA, according to the Health Protection Agency (HPA).

The watchdog encouraged better reporting of cases of Panton-Valentine Leukocidin (PVL) after it was linked to several deaths in the UK.

The strain can cause inflammation of layers under the skin and painful skin infections, such as abscesses and boils.

Over the last six years, cases have risen 10-fold, from 224 in 2005 to 2,227 in 2010, data shows.

The HPA believes this rise could be down to better reporting and increased vigilance as previously many cases of PVL were unidentified infections.

PVL is treatable with antibiotics, but can become resistant to the drugs making it much harder to control. Of all Staphylococcal boil and abscess samples referred to HPA labs, 65% are caused by PVL.

Experts believe they are potentially more aggressive and likely to spread, and require careful treatment. More than a third of the cases are thought to be recurrent, meaning treatment must be made as effective as possible.

Dr Angela Kearns, head of the Staphylococcal reference unit at the HPA, said the findings had helped to improve treatment for patients.

"These latest figures also give us reassurance that the UK is not experiencing the epidemic levels of PVL infection which have been observed in other countries, most notably the United States," she added.

"The risk to the general UK public of becoming infected with PVL is very small. However we will continue to work actively alongside healthcare colleagues to raise awareness of this infection, as well as ensuring appropriate research continues to monitor trends in the infection both in the UK and globally."